Depending on the application and design, not all things you can monitor in the cloud are associated with problems. AWS gives its users an impressive number of metrics associated with its various services, and the only guarantee is that you will never need all of them at once. In the following sections, you will learn about the various issues that impact cloud networking and how to diagnose and ultimately resolve many of them.

IP Address Allocation

Situations where multiple resources have been misconfigured with the same address can happen in the cloud, and discovery of this problem can be challenging. Other common problems include exhausting the IP addresses in a subnet or VPC or allocating IP addresses to multiple VPCs, then having to implement a solution to deal with overlapping IP addresses because the resources in those VPCs must communicate with each other. This is very common in scenarios where different teams are responsible for different...

What sort of information would be needed to diagnose some of these problems? How would a system effectively provide that information to a cloud network engineer? Most importantly, how could that information be consumable and actionable? In this section, you will learn about the kind of metrics and logging that would make the diagnosis of problems possible. Metrics are the measurements of the performance of a cloud network, while logging focuses on the recording of problems and events that can aid in the discovery of problems in a cloud network.

IP Address Management

One of the most fundamental metrics affecting cloud networking is simply knowing how the IP addresses available to use are allocated, where they are allocated, and what remains that can be used to expand the network. AWS provides an IPAM solution that will keep track of all the IP addresses in use and available across your deployment. With this information centrally managed, AWS IPAM allows you...

In this section, you will explore the AWS services supporting monitoring and performance in detail using the AWS tools provided for this purpose, such as the following:

• CloudWatch
• CloudTrail
• VPC Flow Logs
• VPC Traffic Mirroring
• Network Manager

The purpose of monitoring is to aid in capacity planning through the interpretation of trends, to diagnose and troubleshoot issues occurring across your network, and to gain a better understanding of the behavior of applications across your organization. By the end of this section, you should understand the tooling that AWS provides, and, at a high level, which tool is appropriate to use when diagnosing or troubleshooting problems that occur.

Amazon CloudWatch

CloudWatch is the AWS metric logging and alerting service. This book does not focus on the hundreds of AWS services that can use CloudWatch for logging, alerting, and visualization. Instead, the focus of CloudWatch...

This section focuses on how to create logging and alerts for the various services in AWS, followed by some common troubleshooting methods you may be called on to use as a cloud network engineer.

Log Creation for CloudWatch and S3

Logs must be exported somewhere for analysis. No matter what service is being logged, CloudWatch requires a logging group to be created to serve as a container and target for those logs. Commonly, log groups are segregated by function or service.

Creating a log group in CloudWatch is very simple. It can be done via the AWS CLI, SDK, or API, but in this case, it will be done using the AWS console. If the Trailcats administrators found themselves in a situation where a particular server or AWS service needed to be logged for diagnosis of an intermittent, recurring issue, for example, they would need to create a CloudWatch log group to serve as the target to collect these logs. Here is how they could do that:

1. From...

This section will be dedicated to the sort of problems that happen when packets and frames are mismatched along the path of a network flow, as well as how to capture, diagnose, and correct the problem.

Trailcats recently migrated an application to the cloud from the on-premises data center as part of a migration project. After migrating the application to the cloud and setting up connectivity to an AWS TGW over an S2S VPN, users have complained about slowness in application performance. It’s time to investigate the problem. Figure 4.8 shows the relevant traffic flow:

Figure 4.8: On-premises traffic going to cloud resourceIn this case, the application is hosted in the AWS cloud, and the users are connecting to the application over the new WAN connection. To further investigate the slowness problem, consider what changed when migrating the connectivity between a locally hosted data center to one connected over the...

In this chapter, we examined the definition and purpose of monitoring and troubleshooting within the AWS cloud by listing the potential problems, pitfalls, and issues that can cause problems with a cloud network deployment, providing details on each of these potential issues, and the most effective tooling available in AWS to diagnose and troubleshoot them. We then walked through the details of creating some of the most useful (and used) diagnosis and troubleshooting tools in AWS. Understanding the problems that can plague a cloud network, how they can be monitored, and how the problems can be discovered using AWS tools is an important part of administrating a cloud network.